Steel conversion

ABSTRACT

A steel converter having bottom tuyeres supplied from a plurality of solids-weighing tanks which discharge selectively under pressure into a single conduit serving the tuyers. The weighing tanks are isolated from the conduit by individual flexjoints which permit relative motion between their ends, without detrimental stresses as a result of pressure-changes, while maintaining aeration of the material passing through the flexjoint.

States Patent 1 1 Eichinger Dec. 31, 1974 STEEL CONVERSION 2,335,478 11/1943 Bergman 285/301 3,311,418 3/1967 Scrub et a1 302/3 [75] Inventor: F ElchmgenBuxtehude 3,323,905 6/1967 Dobro wsky et a1 75/54 Germany 3,632,173 10/1969 Reuter 302/3 [73] Assignee: Claudius Peters AG, Hamburg,

Germany Primary Examiner-Gerald A. Dost Filed: Jan 1973 Attorney, Agent, or F1rm-Freder1c C. Dreyer v A steel converter having bottom tuyeres supplied from [52] U.S. Cl. 266/34 T, 285/300, 285/301, a plurality of solids weighing tanks which discharge 302/29 selectively under pressure into a single conduit serving gl 'ld 'f' the tuyers. The weighing tanks are isolated from the 0 earc 1 1 1 conduit by individual flex-joints which permit relative 266/41; 285/299, 300, 301; 302/3, 27, 2 motion between their ends, without detrimental 531 64 stresses as a result of pressure-changes, while maintaining aeration of the material passing through the [56] References Cited flex joint UNITED STATES PATENTS 239,621 4/1881 P116111 266/35 4 6 Drawmg guns I! I2 I3 4 5 6 4a 6a 2. 50 i2.

.L .2 1 IL PAIENIEI] BEBE! 1 I974 3 851, 554.

SHEET 10F 2 PATENTEDBEBB 1 1914 3'. 857. 554

SHEEI 2 BF 2 STEEL CONVERSION BACKGROUND OF THE INVENTION The present invention relates to the supply of loose, solid material from plural zones to a single service zone and is more particularly concerned with the weighing and pressure-injection of different solids into the bottom of steel converters.

BRIEF DERSCRIPTION OF THE PRIOR ART Systems are known in which flex-joints are used between relatively movable components to accommodate a necessary motion of one of the components.

However, no prior system is known which satisfactorily provides for such motion in pressure-conveying systems in which solid materials are to be weighed and thereafter to be conveyed in a gas stream. The problems of such a system become more acute when different materials are to be delivered in the same system.

SUMMARY OF THE INVENTION The present invention provides a weighing and pressure-conveying system for plural materials for delivery to a common point at a pressure above atmospheric pressure.

The system of the invention is of unique advantage in the supply of measured quantities of different loose solids into the bottom of steel-converters below the surface of the molten metal therein.

The present invention includes a new flex-joint for conveying loose solids between relatively moveable points without detrimental effects from pressurechanges within the systems and without loss of flowability of the material as it passes through the flex-joint.

BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the invention may be derived from the following description and accompanying drawings in which:

FIG. 1 is a schematic elevation of a system according to the invention;

FIG. 2 is a plan view of the system of FIG. 1;

FIG. 3 is a semi-schematic side view of a flex-joint of FIG. 1 on an enlarged scale;

FIG. 4 is a plan view of the flex-joint of FIG. 3;

FIG. 5 is a sectional view of the preferred form of flex-joint of the invention; and

FIG. 6 is a plan view, on a reduced scale, of the flexjoint of FIG. 5.

DESCRIPTION OF THE PREFERRED SYSTEM As shown in FIGS. 1 and 2, the preferred form of system of the invention includes a plurality of weighing tanks 1, 2 and 3 arranged to receive loose, solid material from separate hoppers 11, 12 and 13, respectively. Selective delivery of material from the hoppers l1 13 is accomplished via conventional flex-joints 4, 5 and 6 having valves 4a, 5a and 6a, respectively.

The weigh tanks 1, 2 and 3 each are mounted on weighing means such as sets of load cells 1L, 2L and 3L, respectively. The tanks 1, 2, and 3 each discharge through novel flex-joints 21, 22 and 23 to an otherwise conventional blowtank 24.

Between each weigh tank and its flex-joint 21 22, and 23, respectively, flow-control is provided by individual valves 21a, 22a and 23a, respectively, each of which is regulated by a suitable control system (not 2 shown) which is responsive to appropriate signals from the load cells 1L through 3L.

The present invention has been found to be of extreme advantage when the blowtank 24 is the means for supplying predetermined quantities of different loose solids to a bottom-blown steel converter (not shown) via its discharge 25 leading to the submerged tuyeres of the converter. Carrier gas under pressure from a conventional source (not shown), is supplied to the blowtank 24 and via a pressurizing inlet 26 to a conveying outlet 27.

As best seen in FIGS. 3 and 4, which detail, for simplicity, only one of the flex-joints of my invention each of which includes a sloped inlet section 14 leading angularly from the weigh tank 3 and meeting a substantially horizontal section 15 which, in turn, joins a sloped outlet-section 16 leading to the blow tank 24.

The horizontal section 15 is formed with an intermediate bellows section 17 which is joined to the rigid sections 15R and 15L by suitable clamping means (not shown). Internally, the flex-joint includes an aerating deck 18 affixed to the inlet 14 and to horizontal section 15R, terminating closely adjacent the outlet section 16. With air or gas supplied under suitable pressure beneath the porous aerating deck 18, material entering on its upper surface is aerated and thus aided in its advance to the outlet section 16. The aerating deck 18 is constructed to be free of this sections 15L and 16, to permit free motion of the sections 15R and 15L without interference from the aerating deck.

An especially important part of my invention is found in the pairs of tie rods 19, 19 which are provided between the rigid, horizontal sections 15R and 15L of each of the flex-joints 21, 22 and 23, respectively. Each of the tie rods 19, 19 is provided with a universal or Cardan coupling 20 and 20 respectively, which permits angular displacement around or transverse to the tie rod, but absolutely prevents longitudinal motion between the components 15R and 15L of the flex-joints 21 23, regardless of the presence or intensity of pressure within the joint.

OPERATION OF THE PREFERRED SYSTEM In operation, the system of FIGS. 1 4 functions according to the cycles dictated by the steelconverter, only a part of which will be described herein in the interest of simplicity.

When material is required from one of the hoppers, for example, hopper 13, the control system closes valve 23a in the outlet of weigh-tank 3, and then opens the fill valve 6a from the hopper 13 to fill that weigh tank 3. When the tank 3 has received its appropriate weight of solids, the load cells 3L cause a further control cycle to close'the intake valve 6a.

At the desired time the contents of the weigh tank 3 are to be delivered to the steel converter, the valve 230 is opened to pass the material therein to the blowtank 24, (the valves 21a and 220 being closed). Pressure is supplied to the blowtank 24 and line 26, to force the material into the discharge 25 and the outlet 27 to the converter.

When the material from weigh tank 3 has been exhausted from the blowtank 24, weighed quantities of different materials may then be discharged from the weigh tanks 1 m2 (or once again from tank 3) according to the desired program.

It is of particular significance in the system of the invention that the tie rods 19 anduniversal joints 20 of the flex-joints 21 23 prevent the intermittent, high pressure supplied to their interior from the blow tank 24 from affecting the weighing of the associated tanks 1 3. Since the horizontal sections 15R and 15L cannot move either away from each other or toward each other, because of the tie rods 19, but are free to move up and down laterally with the motion of the associated weigh tank, there is, essentially, no chance of interference with the accuracy of the weighing operations.

It is also of especial importance that, because of the aerating decks 18, the material entering the flex-joints 21-23 is maintained in a flowable state across the horizontal section 15, thereby assuring delivery of a full charge of material each time.

DESCRIPTION OF THE PREFERRED FLEX-JOINT A particularly effective form of flex-joint of my invention is shown in FIGS. 5 and 6. The flex-joint includes an inlet 34 and outlet 36 and a generally horizontal section 35 including rigid sections 35R and 35L joined by a flexible duct 37. The flexible duct is secured to the sections 35R and 35L by suitable clamps 33R and 33L, respectively.

The section 35R is formed as an upwardly and laterally opening Tee comprising an upward inlet and a branch 31, with a branch 32 joining the flexible duct 37. The section 35L is formed as a downward and laterally-opening Tee comprising a downward outlet and a branch 41, with a branch 42 joining the flexible duct 37.

The section 35R is closed, at branch 31, by an end plate 31a which is removeably secured thereto such as by the bolts shown. The end plate 31a carries a U- shaped channel or plenum chamber 39 thereon which extends through the branch 32, the flexible duct 37 and branch 42 and terminates adjacent the outlet 40. The plenum chamber 39 may have additional rest points such as a shelf 39a on the inner wall of the branch 32. The plenum chamber 39 is closed at its upper surface by a suitable aerating deck 38 and receives aerating or fluidizing gas via a gas inlet 39b in the end plate 31a. The aerating deck carries lateral, material-confining flanges 38a along its edges.

Adjacent its juncture with the flexible duct 37, the branch 32 carries a tapering sleeve 43 which surrounds the plenum chamber 39, aerating deck 38 and flanges 38a. The sleeve 43 extends at least across the gap between the branches 32 and 42, within the flexible duct 37, and prevents spillage of material into the folds or bellows of the flexible duct 37.

The section 35L is closed, at its branch 41, by an end plate 41a which is removablely secured thereto, such as by the bolts shown, for servicing. The end plate 41a has a tubular sleeve 44 thereon which carries an impact plate 45 which is mounted thereon by means of slots 46 which receive fingers or tabs 47 on the plate 45. The plate 45 closely fits against the interior of the branch 41 to close off that area to material flow.

The entire assembly of the flex-joint of FIGS. 4 and 6 is longitudinally tied by means of a pair of tie rods 49, 49 which engage the inlet and outlet sections, 35R and 35L, respectively, by means of appropriate pairs of universal joints 50, 50'.

OPERATION OF THE PREFERRED FLEX-JOINT The operation of the flex-joint of FIGS. 5 and 6 is generally similar to the flex-joint of FIGS. 3 and 4.

' abrasion of the solids impacting against its surface.

Various changes may be made in the details of the invention as described without sacrificing the advantages thereof or departing from the scope of the appended claims.

I claim:

1. In a steel-converter system including a converter vessel having tuyers for the introduction of gases and loose-solid matter below the level of the molten metal in the converter by weighing and pressure-conveying said loose solids through the bottom of said converter, the improvement comprising:

a. a plurality of weighing tanks,

b. means for supplying different solid materials to different weighing tanks,

c. cycling means for cycling the filling and emptying said weighing tanks,

d. pressure-conveying means for receiving and pressure conveying different materials from said different weighing tanks at different intervals to said converter,

e. said cycling means including a valve at the inlet of each weighing tank and f. a valve at the outlet of each weighing tank,

g. a flexible joint associated with the inlet of each weighing tank,

h. a flexible outlet joint associated with the outlet of each weighing tank, said flexible outlet joint including i. a flexible duct section arranged at an angle closely approaching the horizontal,

j. means for conveying solids in said flexible outlet joint from the inlet to the outlet thereof, and

k. means for stabilizing each flexible outlet joint against changes in longitudinal dimension under changes of internal pressure.

2. A steel-converter system according to claim 1 in which said stabilizing means includes tie bars secured to spaced members of said flexible outlet joint on opposite ends of said flexible ducts by means of universal joints.

3. A steel'converter system according to claim 1 in which said conveying means includes aerating means in said flexible outlet joint for conveying solids therein from the inlet to the outlet thereof.

4. A steel converter system according to claim 3 in which said aerating means is mounted on a removeable wall portion of said flexible outlet joint. 

1. In a steel-converter system including a converter vessel having tuyers for the introduction of gases and loose-solid matter below the level of the molten metal in the converter by weighing and pressure-conveying said loose solids through the bottom of said conVerter, the improvement comprising: a. a plurality of weighing tanks, b. means for supplying different solid materials to different weighing tanks, c. cycling means for cycling the filling and emptying said weighing tanks, d. pressure-conveying means for receiving and pressure conveying different materials from said different weighing tanks at different intervals to said converter, e. said cycling means including a valve at the inlet of each weighing tank and f. a valve at the outlet of each weighing tank, g. a flexible joint associated with the inlet of each weighing tank, h. a flexible outlet joint associated with the outlet of each weighing tank, said flexible outlet joint including i. a flexible duct section arranged at an angle closely approaching the horizontal, j. means for conveying solids in said flexible outlet joint from the inlet to the outlet thereof, and k. means for stabilizing each flexible outlet joint against changes in longitudinal dimension under changes of internal pressure.
 2. A steel-converter system according to claim 1 in which said stabilizing means includes tie bars secured to spaced members of said flexible outlet joint on opposite ends of said flexible ducts by means of universal joints.
 3. A steel converter system according to claim 1 in which said conveying means includes aerating means in said flexible outlet joint for conveying solids therein from the inlet to the outlet thereof.
 4. A steel converter system according to claim 3 in which said aerating means is mounted on a removeable wall portion of said flexible outlet joint. 